The present technique relates to an apparatus, a method and a program for a 3D data analysis, and to a microparticle analysis system. More particularly, the present technique relates to a 3D data analysis apparatus that can display measurement data of microparticles in the form of a 3D stereoscopic image, and that can perform an analysis of data, such as population information, by using the 3D stereoscopic image.
For analyzing microparticles, e.g., biologically-relevant particles such as cells, microorganisms, and liposomes, and synthetic particles such as latex particles, gel particles, and other particles for industrial uses, a microparticle measurement apparatus is employed which optically, electrically or magnetically measures the microparticles by introducing a dispersion liquid of the microparticles into a flow passage.
As one example, there is a particle analyzer for discriminating synthetic particles depending on sizes and shapes thereof. Parameters (variables) measurable by the particle analyzer are, e.g., element compositions and particle diameters of the microparticles.
Further, a flow cytometer (flow cytometry) is used in an analysis of the biologically-relevant particles. Parameters measurable by the flow cytometer are, e.g., forward scattered light (FS), side-way scattering (SS), fluorescence (FL) and impedance of microparticles. The forward scattered light (FS), the side-way scattering (SS), and the fluorescence (FL) are used as parameters indicating optical characteristics of cells and microorganisms (both of which are referred to simply as “cells” hereinafter), and the impedance is used as a parameter indicating electrical characteristics of cells.
More specifically, first, the forward scattered light is light that is scattered forward at a small angle with respect to an axis of laser light. The forward scattered light includes scattered light, diffracted light, and refracted light, which are generated from the laser light at a cell surface. The forward scattered light is primarily used as a parameter indicating the size of the cell. Next, the side-way scattering is light scattered at an angle of about 90 degrees with respect to the axis of the laser light, and such scattered light is generated upon the laser light impinging against a granule, a nucleus, etc. within a cell. The side-way scattering is primarily used as a parameter indicating an internal structure of the cell. Further, the fluorescence is light generated from a fluorescence dye labeled in a cell. The fluorescence is used as a parameter indicating, e.g., the presence or the absence of a cell surface antigen recognized by an antibody that is labeled by the fluorescence dye, and an amount of nucleic acids to which the fluorescence dye is coupled. Moreover, the impedance is measured by the electric resistance method and is used as a parameter indicating the volume of the cell.
For analyzing data measured by the flow cytometer, a data analysis apparatus is employed which creates and displays a chart representing a characteristic distribution of cells within a cell mass by plotting measurement values of the individual cells with any of the measurement parameters set on a coordinate axis. A one-dimensional distribution chart including one measurement parameter is also called a histogram that is created as a graph with the measurement parameter set on an X-axis and a cell number (count) set on a Y-axis. Furthermore, a two-dimensional distribution chart including two measurement parameters is also called a cytogram. The cytogram is created by plotting individual cells, based on measurement values of the cells, in a coordinate plane in which one measurement parameter is set on an X-axis and the other measurement parameter is set on a Y-axis.
By setting regions on the histogram or the cytogram, statistical data can be obtained regarding cells present in each region. A commonly used example of the statistical data is a frequency distribution (population information) representing at what a rate target cells are contained in a cell mass. The frequency distribution is calculated as a rate at which cells present in each region set on the histogram or the cytogram occupy in the entire cell mass.
For example, when it is known that the target cell exhibits a value of not less than a certain value for a predetermined parameter, a process of calculating a distribution frequency of the target cell based on the histogram is started by dividing the histogram into two parts at the certain value on an X-axis. With the division, the histogram is partitioned into a region where the parameter is not less than the certain value (i.e., a region where the target cell exists) and a region where the parameter is less than the certain value (i.e., a region where non-target cells exist). A data analysis apparatus calculates, for each of the set regions, the distribution frequency from the number of the cells present in the relevant region. Also, in the case using the cytogram, a process of calculating a distribution frequency is started by dividing the cytogram into four regions at the certain value on each of an X-axis and a Y-axis. With the division, the cytogram is partitioned into a region where two parameters are both not less than the certain value (i.e., a region where the target cell exists) and a region where at least one of the two parameters is less than the certain value (i.e., a region where non-target cells exist).
PTL 1 proposes “An analysis apparatus comprising measurement data acquisition means for acquiring first, second and third measurement data from an analyte, three-dimensional distribution map creation means for creating a three-dimensional distribution map that represents a distribution of a formed element, which is contained in the analyte, with the first, second and third measurement data set on axes, region setting means for setting a demarcated region on the three-dimensional distribution map in a changeable manner, and reference distribution map creation means for creating, for the formed element belonging to the demarcated region set by the region setting means, at least one of a two-dimensional distribution map with the first and second measurement data set on axes and a frequency distribution map with the first measurement data set on an axis” (see Claim 9 of PTL 1). According to the proposed analysis apparatus, the demarcated region can be set on the three-dimensional distribution map while referring to the two-dimensional distribution map (cytogram) and the frequency distribution map (histogram), which maps are displayed along with the three-dimensional distribution map. Additionally, the three-dimensional distribution map in the proposed analysis apparatus is displayed in a planar view on a display, and it is not displayed in a stereoscopic view.
In relation to the present technique, the binocular stereoscopic solid image technique (3D stereoscopic image technique) will be described below. To produce a binocular stereoscopic solid image, two images are first prepared which are obtained when looking at an object by a right eye and a left eye, respectively. Then, those two images are displayed at the same time such that the image for the right eye is displayed to only the right eye and the image for the left eye is displayed to only the left eye. As a result, an image perceived by eyes of a user when looking at the object in a three-dimensional space is reproduced, thus enabling the user to perceive the object in a stereoscopic view.
3D displays capable of providing a stereoscopic view are mainly practiced as (a) spectacle type, (b) naked eye type, and (c) viewer type. Of those types, (a) spectacle type is further classified into an anaglyph type, a polarization filter type, and a time division type. Also, (b) naked eye type is classified into a parallax barrier type and a lenticular type, and (c) viewer type is classified into a stereoscope type and a head mount type.